SMAC-Talk: A Natural Language Extension of the StarCraft Multi-Agent Challenge for Large Language Models Researchers introduced SMAC-Talk, a natural language extension of the StarCraft Multi-Agent Challenge designed to evaluate large language model-based agents in cooperative multi-agent environments. The benchmark features decentralized control, partial observability, and a natural language communication channel that tests agent coordination and trust, including scenarios with a deceptive communicator. The open-source release provides three benchmarking agents using Qwen3.5 models to study how reasoning structure, memory, and model scale affect multi-agent coordination. arXiv:2606.04202v1 Announce Type: new Abstract: As LLMs become more widely deployed, they are increasingly expected to work alongside other AI agents rather than operating in isolation. Effective coordination in these settings requires agents to communicate, share information and make decisions under uncertainty. We introduce SMAC-Talk, a natural language extension of the StarCraft Multi-Agent Challenge for evaluating LLM-based agents in cooperative multi-agent environments. The environment has several key features such as decentralized control, partial observability and long-horizon decision making. SMAC-Talk includes a natural language communication channel which is used to probe agent coordination and trust. We use this communication channel to construct different evaluation scenarios, including settings with an embedded deceptive communicator that tries to disrupt and deceive allies through communication alone. We provide three agents for benchmarking using 4 models from the Qwen3.5 family and study how reasoning structure, memory and model scale affect coordination between agents. We release SMAC-Talk as an open benchmark to support the research community in developing and evaluating LLM agents in cooperative multi-agent settings.